This sounds a lot like its hinting at the bodies proactiveness in preparing for evolution of any sort.
Answer: Option C.
The number of protons and neurons it's contain.
Explanation:
Mass number of an atom is also called atomic mass of an atom which is some what expressed in Dalton i.e 1/2. The mass number is the total number of protons and neutrons altogether called nucleons in an atomic nucleus.
Take your shirt off, wave it round ya head like a helicopter
